The present invention relates to load bearing fabric assemblies and methods for securing a load bearing fabric to a support structure.
“Load bearing fabrics” are high strength, highly durable textiles typically woven from TPE (thermoplastic elastomer) monofilaments and conventional yarns. Load bearing fabrics can have greater strength and durability characteristics than spring steel and other conventional load bearing materials. In addition to enhanced strength and durability, load bearing fabrics are lightweight and typically relatively elastic. Load bearing fabrics are visually appealing and therefore are often exposed during use.
Load bearing fabrics must be properly attached to a support structure to provide the desired strength and durability. One known method for attaching a load bearing fabric to a support structure is to use a pair of interfitting attachment components, generally referred to as a “carrier” and a “frame.” In this method, the carrier is attached to the fabric and the frame is attached to the support structure. The combined carrier and fabric are intersecured with the frame. In many conventional applications, the carrier is installed within the frame so that the fabric is held in a stretched condition. In some applications, the action of installing the carrier within the frame causes the stretching in the fabric to occur. In other applications, the fabric is stretched before installation of the carrier within the frame. In any event, the stretch applied to the fabric stresses the fabric and the attachment of the load bearing fabric to the carrier. If improperly attached, the fabric may separate from the carrier. For example, the bond itself may fail or the fabric may unravel or separate along the periphery of the fabric.
One widely used method for intersecuring the carrier and the fabric is to mold the carrier directly onto the fabric. With this method, the fabric is typically placed within a mold and the carrier is molded with TPE around the fabric. The fabric is thus encapsulated within the carrier. Conventional knowledge indicates that the melt temperature of the TPE used to make the carrier must be about the same as or lower than that of the TPE monofilaments in the fabric. Otherwise, the heat of the molten material may cause the fabric to deteriorate or decay. This requirement restricts the type of TPE used for the carrier to those having a particular melt temperature. Since the stiffness of TPE typically increases as the melt temperature of the TPE decreases, the stiffness of the carrier is thereby limited by the TPE used within the load bearing fabric.
In some applications, it would be advantageous to be able to vary the stiffness of a carrier while using the same fabric. Thus, an improved method for binding the fabric to the carrier is highly desirable.
After the fabric is bonded to the carrier, visual inspection of the bond between the carrier and the fabric may display certain defects. For example, a visual inspection may be able to detect if the fabric was not properly encapsulated by the carrier. However, in some circumstances, the fabric may appear to be properly bonded to the carrier but in fact is not. In these situations, after the carrier is installed within the frame and the fabric has been further stressed, the fabric may pull out of the carrier. A means for detecting insufficient encapsulation of the fabric, unraveling of the fabric or other attachment defects after the carrier is installed in the frame is thus also highly desirable.